Thema "Betreff: My new Vitodens 100 Combi Boiler takes over 3 mins to resume heating after DHW use" in Gas

My new Vitodens 100 Combi Boiler takes over 3 mins to resume heating after DHW use

Josh88 — Fri, 03 Apr 2026 04:09:44 GMT

My new Vitodens 100-W B1KE-120 combi boiler that was installed 2 days ago takes over 3 mins to resume heating the house after using domestic hot water. So any time anyone rinses a cup or washes their hands, the heat is dead off for over 3 mins.
Is this normal??
Thank you for your feedback.
-Josh

Betreff: My new Vitodens 100 Combi Boiler takes over 3 mins to resume heating after DHW use

Claus-Vito — Fri, 03 Apr 2026 04:56:54 GMT

Moin Josh88

This behavior in combination boilers is often a matter of settings (the so-called lockout time or post-run time). It's normal for the unit to pause briefly after heating water, but many people find 3 minutes for every quick hand wash too long. Technically, this is often referred to as the "fuel-saving function" or "cycle lockout."

Claus-Vito

Betreff: My new Vitodens 100 Combi Boiler takes over 3 mins to resume heating after DHW use

Josh88 — Fri, 03 Apr 2026 10:16:43 GMT

Hello Claus-Vito, thank you for those insights! So this is totally normal behavior. Okay, that’s good to know.
Is there a way to have the furnace turn on the burner and resume heating the house within 30 seconds of the DHW no longer being used? Do the available settings allow such specific behavior?

Thanks again.
-Josh

Betreff: My new Vitodens 100 Combi Boiler takes over 3 mins to resume heating after DHW use

Claus-Vito — Fri, 03 Apr 2026 10:46:19 GMT

Moin.

In the service level (menu b2 or coding 2 on older models), technicians can adjust specific parameters for the pump overrun time or the switching delay.

Shortening these times ensures that the three-way valve returns to the heating position more quickly. Note: These settings should only be made by a qualified heating engineer to avoid malfunctions or cycling problems with the burner.

DIY tip: First, check that all hot water taps are completely closed. If the boiler remains in hot water mode after 30 seconds (indicated by the tap symbol on the display), the internal sensor is likely detecting residual flow.

Dripping taps: Even a minimal flow (e.g., due to a defective tap) keeps the device stuck in hot water mode.

Greeting Claus-Vito

Betreff: My new Vitodens 100 Combi Boiler takes over 3 mins to resume heating after DHW use

Josh88 — Fri, 03 Apr 2026 11:14:34 GMT

Hi Claus-Vito, thank you again for your thoughts.
There are definitely no leaky taps. I run a tight ship here. 😀

The furnace is brand new, just out of the box 2 days ago. Is it possible the 3-way valve just needs to break in a little? Like loosen up?

Thanks!

-Josh

Betreff: My new Vitodens 100 Combi Boiler takes over 3 mins to resume heating after DHW use

divanc — Fri, 03 Apr 2026 15:38:33 GMT

Hello @Josh88

The time for the internal pump to run after the domestic hot water heating can be set in the parameters.

Note: To avoid damaging the boiler, do not set the run on time to < 120 sec.

Best regards

Betreff: My new Vitodens 100 Combi Boiler takes over 3 mins to resume heating after DHW use

Josh88 — Sat, 04 Apr 2026 17:10:12 GMT

Thank you, divanc! …strangely, it is currently set to 0 (see pics). The system was just commissioned 3 days ago, right out of the box, new. It’s either a 2025 or even 2026 model. …so…I’m just the homeowner, so not sure if I should set it to some value myself. …don’t want to break it. 😂😮